Brake adjustment indicating means



March 3,1936. w BAIRD 2,032,392

BRAKE ADJUSTMENT INDICATING MEANS Filed May 25, 1929 'IIIIII/IJ/IIIi/IIAYIA Patented Mar. 3, 1936 V UNITED STATES PATENT OFFIE BRAKE ADJUSTMENT INDICATING MEANS John W. Baird, Glen Ellyn, Ill.

Application May 23, 1929, Serial No. 365,263

Z'Claims. (Cl. 177-311) This invention relates generally to signal de- Fig. 5 is a diagram showing the electrical convices and has particular reference to automobile nections. brake adjustment indicating means. Fig. 6 is a view showing a modified contact ring. At the present time automobiles are equipped Referring now to the several illustrations, l

with either two or four wheel brakes. This inindicates a motor vehicle frame which is pro- 5 vention is adaptable for use with either two or vided with wheels H having brake drums generalfour wheel brakes for indicating the adjustment ly indicated in Fig. l, by the numeral I2. An thereof. electric storage battery I3 is provided which is One of the objects of the invention is to proconnected from its positive terminal l3 through vide means for indicating, to the motor vehicle a switch I! with leads I 8 to the terminals of the 10 operaton'the condition of the brake adjustment filaments of a plurality of electric light bulbs M; of any particular wheel relative to the brake adthere being one bulb for each brake set. The justments of the other wheels of the vehicle. electric light bulbs l4 may be conveniently mount- Another object of the invention is to provide ed upon the dash board'l5.

visible means for indicating which, if any, of the Th negative t rminal l3 of the battery I3 is 15 brakes are locked or out of adjust e tgrounded to the frame It) at l6, and the negative Whe t e brakes O a m o Vehicle a D D- terminals ofthe bulb filaments are connected er y adjust d, t e v t of the feet brake through the leads ill to the insulated spring- D bleke Will Simultaneously apply pressed contacts generally indicatedby which 0 all of the brake bands with equal pressure against are mounted in t brake cover i k 2 l, 20 the wheel brake drums but when one or more of The pring-pressed t t 20 h comprise the brakes are Out Of adjustment, One more Of a metal sleeve 20 which is threaded exteriorly t brak ands l engage their respective for mounting within the brake cover disk 2| and drums with the applied pressure while the remainprovided with 100k nuts 20 The outer, end. of

ing brake bands will fail or possibly only slightly the sleeve 29A is provided with a n 25 engage their respective drums causing obviously head formation no f r suitable Wrench engage e loss of the braking p w of s unengeged ment to facilitate its threaded insertion and lonema brakesgitudinal adjustment into the brake cover disk 2|. y invention permits the motor Vehicle drivel Screw mounted within the interior of the sleeve to test the braking condition of the brakes at will, A is t m member 20 of electrically in- 30 and to positively determine during the Operation sulated material having a restricted opening 20 0f the V Which of the brakes are locked? for the slidably mounted metal contact pin 20 If all the brakes are equally adjusted, Vlfiiblev the outer projecting end of which is rounded and 3 electric light signals, one for each brake, will the inner end f which is provided t an elearlyindieete Such eondl'tientegral head 20 normally resting against the With t above d other Objects in View, y shoulder formed within the member 20 invention consists in the novel combination and The member 20 1 l threaded interiorly construction of the parts and members shown in from t Outer or exposed end for the screw 40 pr f r m im nt in h a mp yi plug 20 which is also made of electrically insu- 40 drawing, described in the following specifications, lated material and formed with a hexagon head and particularly po Out in the appended ZD for suitable wrench engagement to facilitate claims. its threaded insertion within the member 20 R e in t the illustr tion Fi 1 is a The plug 20 is provided with a longitudinal bore gremmatie p V w Of h frame and Wheels of for the extension 20 of a metallic integral disk 45 a motor vehicle and showing the general arrange- 20 A coil spring 20 is mounted between the m n a d appl a of y nv n to four disk 20 and the head 20 to positively retain W eel b e the pin 20 in its normal position, as shown in Fig. 2 is a cross section taken on line 2-2 of Fi 4, projecting beyond the end of the mem- Fig. 1. ber 20 for intermittent engagement with a con- 50 Fig. 3 is a vertical section taken through the tact ramp 22 which is rigidly mounted to the wheel brake bands and brake drum. inner side of the rotatable brake drum 23 and Fig. 4 is a longitudinal section taken through obviously arranged radially to contact with the the insulated positive lead which is mounted on rounded end of the pin 20 the brake drum cover disk. The outer end of the extension 20 is pro- 55 vided with a pocket to receive the end of the lead or conductor l9 which is soldered therein.

It is now readily apparent that the lead I9 is conductively connected with the disk 20 and through the coil spring 20 with the pin 20 and that the grounded side of the electric light bulb circuits will be closed or completed in each revolution of the wheel brake drums 23 during the engagement of the ramp contact 22 with the spring-pressed pin 20 the coil spring 20 permitting a slight inward sliding movement of the pin 20 during its contact with the ramp contact 22.

It is also obvious, that when the switch I! is closed, the electric circuits to all of the bulbs M will be intermittently closed by the repeated contacting of the ramp 22 with the pin 20 to thus cause an intermittent flashing signal of the electric bulbs l4.

Assuming now that the brakes are properly adjusted all of the four bulbs M will under such conditions continue to flash successive light signals indicating to the driver of the motor vehicle that all wheels with their respective brake drums are revolving. If upon brake application, any of the brakes be out of adjustment whereby one or more of the brakes act quicker to lock such wheels against rotation, the respective or particular bulbs connected in circuit therewith, will cease to continue their intermittent fiashing signals and will thus indicate to the driver which of such brakes are locked whereupon the brakes may then be adjusted to insure their simultaneous braking action. If all of the light bulbs should simultaneously cease flashing it would indicate that all of the brakes were properly coacting in braking action.

It is obvious, that if one or more of the brakes happen to look at the moment of the contact of the pin 20 with the ramp 22 a continuous light signal will appear which will readily be understood.

It is readily understood also that the ramp contacts 22 may be extended to any desirable length to afford a longer duration of the light signal and that instead of one ramp, two or more ramps may be arranged or aligned in the circle for repeated long contacts with the pin 20 Fig. 6 shows a modified contact ring 24 which may be rigidly fixed on the inner face of the brake drums 23 and conductively connected thereto. A plurality of non-conductive fiber strips 25 may be inserted in the face of the ring 24 to break the circuit as the end of the pin 20 rides over the ring 24.

The ring 24 may be employed as a substitute for the ramp 22 to produce long light signals with short interruption.

Other changes may be made in the construction and arrangement of the parts and members without departing from the spirit of my invention as defined in the appended claims.

I claim:

1. In an indicating means for testing relative efficiency conditions of the brakes of the wheels of a vehicle, including a brake for each wheel, an electrically controlled signal for each wheel, a normally open circuit for each signal, means for simultaneously connecting all of said circuits with a source of energy when test is desired, and means controlled by the movement of each wheel to intermittently energize the signal for that wheel, whereby in the normal operation of the vehicle during test the signals operate intermittently with substantial uniformity prior to brake application, said signals following brake application being controlled by the movement of each wheel as governed by its brake, whereby under unequal brake adjustments the, speed of one Wheel will be retarded sooner than the speed of another wheel and the signals of the retarded wheel will be out of normal uniformity with the other signals, to thereby indicate unequal brake adjustments.

2. A construction as defined in claim 1, wherein each signal is energized during each revolution of the wheel for which that signal is arranged and wherein any interruption in the time period of such signal will indicate a retardation in the normal revolution of the wheel, to thereby utilize the signals of all wheels in their relative time periods of energization as indicating after brake application whether one or more of the wheels are less retarded in revolution by the brakes than others of the wheels.

JOHN W. BAIRD. 

